Volume-II of IV - GAIL

determination of surface profile – Stylus
instrument procedure.
g) SIS-055900 : Pictorial surface Preparation Standard
for Painting Steel Surfaces.
h) SSPC-SP 1 : Steel Structure Painting Council.
In case of conflict between the requirements of this specification and that of above
referred documents, the requirements of this specification shall govern.
The Contractor shall be familiar with the requirements of these documents and
shall make them readily available at the site to all personnel concerned with
carrying out the works specified in this specification.
3.0 MATERIALS AND EQUIPMENT
3.1 Field Joint Corrosion Coating Material
Field joint anti-corrosion coating material shall be either heat shtrinktable
wraparound sleeve or cold applied tape suitable for a maximum operating
temperature of (+) 60°C (Tmax) and shall conform to designation EN 12068 – C HT
60 UV. In addition the field joint anti-corrosion coating shall comply the
requirements specified in para 3.2 of this specification.
3.1.1 Heat Shrinkable Wraparound Sleeve
Heat shrinkable wraparound sleeve shall consist of radiation cross-linked thermally
stabilised, ultraviolet resistant semi-rigid polyolefin backing with a uniform thickness
of high shear strength thermoplastic/copolymer hot melt adhesive. The joint
coating system may consist of a solvent free epoxy primer applied to the pipe
surface prior to sleeve application. The backing shall be coated with thermochrome
paint which will change colour when the desired heat during shrinking is attained.
The wraparound sleeve shall be supplied in pre-cut sizes to suit the diameter and
the requirements of overlap.
The total thickness of heat shrinkable wraparound sleeve in the as applied condition
shall be as follows :
Pipe Size
Thickness (mm)
(Specified Outside Diameter)
On Pipe Body On Weld
Average Min. Bead
(Min.)
Upto 10¾” (273.1mm)
Over 10¾” (273.1mm) to below 20” (508.0mm)
From 20” (508.0mm) to below 32” (813.0mm)
2.0 1.8 1.6
From 32” (813.0mm) and above 2.4 2.2 2.0
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